Clock



FIG. 1 is a front perspective view of a clock showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines in the views are for the purpose of illustrating portions of the clock that form no part of the claimed design. 

CLAIM The ornamental design for a clock, as shown and described. 